JP6708595B2 - Sports shoe sole structure - Google Patents

Description

The present invention relates to a sole structure for sports shoes, and more particularly, to a sole structure capable of controlling the flexibility of the forefoot region by suppressing excessive bending of the forefoot region.

European Patent Publication No. 3146862 describes footwear including a wavy (zigzag) midsole in which peaks and valleys are alternately repeated in the front-back direction of the sole (paragraph [0018], FIG. 1, FIG. See FIG. 2). In this midsole, voids are formed between adjacent peaks (that is, above the valleys) and between adjacent valleys (that is, below the peaks). , And the gaps between the valleys extend over the entire width of the midsole (see paragraph [0018], FIGS. 1 and 2).

In the one described in the above-mentioned European Patent Application Publication No. 3146862, when the valley portion of the wavy (zigzag-like) midsole comes into contact with the ground contact surface, the compressive force acts on the valley portion, and above the valley. By deforming the voids, the cushioning property is secured (see paragraphs [0019] to [0020]).

Further, in Japanese Patent No. 3403952, a sole bending groove is formed in the forefoot region of the outsole, and an upper midsole made of a flexible EVA sponge material is arranged on the upper surface of the outsole. (See FIG. 1). The sole bending groove of the outsole penetrates the outsole in the thickness direction, and the upper midsole is exposed at the bottom of the sole bending groove.

In the one described in the above-mentioned Japanese Patent No. 3403952, when the outsole is bent, the forefoot region of the outsole is bent along the sole bending groove, so that the sole flexibility is secured.

However, in the one described in the above-mentioned European Patent Application Publication No. 3146862, when the midsole is bent, excessive bending may occur locally at the valley portion of the zigzag midsole, When such excessive bending occurs locally, energy loss occurs due to the excessive bending.

Further, in the one described in the above-mentioned Japanese Patent No. 3403952, a soft upper midsole is exposed at the bottom of the sole bending groove, and therefore, when bending along the sole bending groove, excessive Bending may occur and energy loss may occur.

The present invention has been made in view of such conventional circumstances, and a problem to be solved by the present invention is a sole capable of controlling the flexibility of the forefoot region by suppressing excessive bending of the forefoot region. To provide a structure.

A sole structure of a sports shoe according to the present invention is disposed on an upper side of a forefoot region, has an upper surface serving as a sole contact surface with which a sole of a wearer comes into contact, and an upper midsole made of a soft elastic member, and , A lower midsole that is arranged below the forefoot region and that is provided so as to come into contact with the lower surface of the upper midsole, and that is composed of a soft elastic member And an outsole having a plurality of sole bending grooves extending substantially in the sole width direction. Both the lower surface of the upper midsole and the upper surface of the lower midsole have corrugated surfaces formed of corrugations that substantially advance in the front-back direction of the sole , each having a thick portion, and having a corrugated convex shape. The ridge line that connects the vertices and the valley line that connects the deepest part of the wavy concave shape extend substantially in the sole width direction, and the upper midsole and the lower midsole have hardness differences. is doing. At least a portion of the wave-shaped edge line of the upper midsole of relatively high hardness relative to the lower midsole is not overlap the upper and lower direction with respect to each of a plurality of sole curved groove outsole, upper mid The thick portion of the sole is arranged at each position of the plurality of sole bending grooves , or at least a part of the corrugated ridge line of the lower midsole having a relatively high hardness with respect to the upper midsole is formed on the outsole. Each of the plurality of sole bending grooves overlaps in the vertical direction, and the thick portion of the lower midsole is arranged at each of the plurality of sole bending grooves .

According to the present invention , both the lower surface of the upper midsole and the upper surface of the lower midsole have corrugated surfaces, the upper midsole and the lower midsole have a hardness difference, and the upper midsole has a relatively high hardness. or at least a portion of the wave-shaped ridge line of the lower midsole relatively high hardness are overlapped vertically to each sole bending groove outsole, to the position of each sole bending groove outsole, relative The ridge line of the corrugated surface on the lower surface of the upper midsole having a high hardness or on the upper surface of the lower midsole having a relatively high hardness is arranged. That is, at the position of each sole bending groove of the outsole, the thick portion (that is, the high rigidity portion) of the high hardness upper midsole having the corrugated surface on the lower surface or the high hardness lower portion having the corrugated surface on the upper surface. The thick part (that is, the high rigidity part) of the midsole is arranged.

At the time of bending of the sole structure, when the forefoot region of the sole structure tries to bend along each sole bending groove of the outsole, when the sole structure has a relatively high hardness arranged at the position of each sole bending groove. The thick parts of the upper midsole or the relatively hard lower midsole tend to bend at the same time, but since these thick parts are high rigidity parts, the bending resistance is large, and each sole bend of the sole structure is bent. Suppresses local excessive bending along the groove. As a result, the flexibility of the forefoot region can be controlled, and the occurrence of energy loss due to local excessive flexion can be prevented.

In the present invention, the corrugated ridge line vertically overlaps with each sole bending groove in any of the inner instep side portion, the outer instep side portion, or the sole width direction central side portion of the forefoot region.

In the present invention, the plurality of sole bending grooves are composed of first and second sole bending grooves that are arranged at intervals in the front-back direction of the sole with the middle toe joint of the foot of the shoe wearer interposed therebetween. ..

In the present invention, the third sole bending groove is provided between the first and second sole bending grooves, and the third sole bending groove extends from the first and second sole bending grooves in the front-back direction of the sole. It is arranged at intervals.

In the present invention, each sole bending groove is open to at least one of the inner instep side end and the outer instep side end of the forefoot region.

In the present invention, each sole bending groove closes both the inner instep side end and the outer instep side end of the forefoot region.

In the present invention, each sole bending groove has a slit that penetrates the outsole in the thickness direction.

In the present invention, a groove is further formed on the lower surface of the lower midsole at a position corresponding to the slit.

In the present invention, the wavy ridge lines and valley lines extend over the entire sole width direction of the forefoot region.

In the present invention, the wavy ridge line and the valley line are arranged only in the sole width direction central side portion of the forefoot region.

As described above, according to the sole structure of the sports shoe according to the present invention , at least a part of the corrugated ridge line of the relatively high hardness upper midsole or the relatively high hardness lower midsole is outsoleed. since so as to overlap vertically with each sole bending groove of, when the forefoot region of the sole structure tries bent along the sole bending groove outsole during bending of the sole assembly, the sole bending The thick portion (high rigidity portion) of the relatively high hardness upper midsole or the relatively high hardness lower midsole arranged at the position of the groove tries to bend at the same time to generate a large bending resistance. Suppresses local excessive flexion along each sole flexion groove of the sole structure to control the flexibility of the forefoot region, preventing energy loss due to local excessive flexion it can.

1 is a schematic bottom view of a sole structure of a sports shoe according to an exemplary embodiment of the present invention. FIG. 3 is a side view on the inner shell side of the sole structure (FIG. 1). It is an outer shell side view of the said sole structure (FIG. 1). FIG. 4 is a schematic sectional view taken along line IV-IV of the sole structure (FIG. 1). FIG. 5 is a schematic cross-sectional view taken along line VV of the sole structure (FIG. 1). FIG. 6 is a schematic cross-sectional view taken along line VI-VI of the sole structure (FIG. 1). It is a VII-VII line sectional schematic diagram of the said sole structure (FIG. 1). FIG. 8 is a schematic cross-sectional view of the sole structure (FIG. 1) taken along the line VIII-IIIV. FIG. 2 is a diagram in which the skeleton structure of the foot is entered in FIG. 1, and is a view for explaining the positional relationship between the sole flexion groove and the skeleton structure of the foot. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a partially enlarged view of FIG. 3. FIG. 5 is a partially enlarged view of FIG. 4. FIG. 11 is a partially enlarged view of FIG. 10 and is a view for explaining the depth of the sole bending groove. FIG. 6 is a schematic bottom view of a sole structure according to a first modified example of the present invention. FIG. 15 is a side view of the inside of the sole structure (FIG. 14). FIG. 15 is a side view of the sole structure (FIG. 14) on the outer shell side. FIG. 15 is a schematic cross-sectional view taken along line XVII-XVII of the sole structure (FIG. 14). FIG. 16 is a partially enlarged view of FIG. 15. FIG. 17 is a partially enlarged view of FIG. 16. FIG. 18 is a partially enlarged view of FIG. 17. FIG. 20 is a partially enlarged view of FIG. 19 and is a view for explaining the depth of the sole bending groove. FIG. 9 is a bottom schematic view of a sole structure of a sports shoe according to a second modified example of the present invention. FIG. 23 is a side view of the sole structure (FIG. 22) on the instep side. FIG. 23 is a side view of the sole structure (FIG. 22) on the outer shell side. FIG. 23 is a schematic cross-sectional view taken along line XXV-XXV of the sole structure (FIG. 22 ). FIG. 13 is a side view of the sole structure of the sports shoe according to the third modified example of the present invention on the inner side. FIG. 14 is a partial side view on the inner instep side of a sole structure of a sports shoe according to a fourth modified example of the present invention. FIG. 14 is a partial side view of the inside structure of the sole structure of the sports shoe according to the fifth modified example of the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 13 are views for explaining a sports shoe sole structure according to an embodiment of the present invention. Here, running shoes are taken as an example of sports shoes. In the following description, upper (upper/upper) and lower (lower/lower) represent the vertical positional relationship of the shoe, and front (front/front) and rear (rear/rear) , Represents the positional relationship in the front-rear direction of the shoe, and the width direction refers to the left-right direction of the shoe. That is, in the case of FIG. 1 as an example, the upper side and the lower side respectively refer to the back side and the front side of the paper in the same figure, and the front and rear sides refer to the upper side and the lower side in the same figure, respectively, and the width The direction indicates the left-right direction in the figure. Further, in FIG. 1, H indicates the heel of the sole structure, M indicates the middle foot, and F indicates the front foot.

As shown in FIGS. 1 to 4, the sole structure 1 includes an upper midsole 2 arranged on an upper side, a lower midsole 3 arranged on a lower side, and an outer part mounted on a lower surface of the lower midsole 3. It has a sole 4. The upper and lower midsoles 2 and 3 extend from the heel portion H of the sole structure 1 through the middle foot portion M to the front foot portion F. Grooves formed on the lower surface of the outsole 4 for improving anti-slip properties/grip properties/durability/design effect or weight reduction are omitted for convenience of illustration.

The upper surface 2a of the upper midsole 2 constitutes a sole contact surface with which the sole of the wearer directly contacts or indirectly contacts through an insole or the like. As shown in FIGS. 2 to 4, the upper surface 2a extends from the heel portion H of the sole structure 1 through the middle foot portion M to the front foot portion F. As shown in FIGS. 5 to 8, a pair of left and right rising portions 20 that rise upward are provided on both sides of the upper surface 2a in the width direction.

As shown in FIGS. 1 to 4, the lower surface 2 b of the upper midsole 2 has a corrugated surface, and the upper surface 3 a of the lower midsole 3 has a corrugated surface corresponding to the corrugated lower surface 2 b of the upper midsole 2. It has a shape surface. The lower surface 2b of the upper midsole 2 and the upper surface 3a of the lower midsole 3 are fixed by adhesion or the like in a state where the peaks and valleys and the valleys and peaks of the respective wave shapes are engaged. 2 to 4 show an example in which the wave shapes of the upper and lower midsoles 2 and 3 are extended from the heel portion H of the sole structure 1 to the middle foot portion M to the front foot portion F. In the sole structure 1 according to the present embodiment, the corrugations of the upper and lower midsoles 2 and 3 may be provided on at least the front foot portion F.

The wave-shaped mountain lines (ridge lines) and valley lines on the lower surface 2b of the upper midsole 2 are indicated by broken lines in the region of the forefoot F in FIG. Here, a wave-shaped mountain line (ridge line) means a line formed by connecting convex vertices, and a wave-shaped valley line means a line formed by connecting concave deepest portions. The wave-shaped peak line (ridgeline) of the lower surface 2b of the upper midsole 2 coincides with the valley line of the upper surface 3a of the lower midsole 3, and the wave-shaped valley line of the lower surface 2b of the upper midsole 2 is the lower midsole. 3 coincides with the mountain line (ridge line) on the upper surface 3a. In FIG. 1, five broken lines are shown. Among these broken lines, a broken line 2b ₁ indicates a wave-shaped ridgeline of the lower surface 2b of the upper midsole 2, and each broken line 2b adjacent in the front-rear direction. The broken line 2b ₂ between ₁ indicates the corrugated valley line of the lower surface 2b of the upper midsole 2.

The ridge line 2b ₁ and the valley line 2b ₂ substantially extend in the sole width direction, and each is a curve that is gently curved and extends in the entire sole width direction. Here, the word "substantially" is included only when the ridge line 2b ₁ and the valley line 2b ₂ are in the strict width direction orthogonal to the sole front-rear direction center line (IV-IV line in FIG. 1). Of course, it is also intended to include the case where it intersects at an angle with this. Further, each ridge line 2b ₁ and valley line 2b ₂ gradually incline toward the instep side toward the front so as to follow the moving direction of the load during traveling, and the lower surface 2b of the upper midsole 2 is The wavy shape of is substantially proceeding in the front-back direction of the sole. The word "substantially" is used here not only when the wave shape is in the strict sole front-rear direction that travels along the sole front-rear direction centerline, but also when the wave shape travels diagonally at an angle. Is also included.

As shown in FIG. 1, the sole structure 1 has a plurality of sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ on the bottom surface side of the front foot portion F. The sole bending grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ are arranged at positions vertically overlapping with the corrugated ridge lines 2 b ₁ on the lower surface 2 b of the upper midsole 2. In FIG. 2 to FIG. 4, the ridgeline 2b ₁ extends in the direction perpendicular to the paper surface of each figure, and is arranged above the corresponding sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′, and the sole The bent grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ are opposed to each other. Here, the ridgeline 2b ₁ extends over the entire sole width direction, that is, from the inner instep side portion of the forefoot F to the outer instep side portion through the width direction central portion, the sole bending grooves G ₁ , G ₂ , G _{3, G 3} 'and are overlapped vertically, the sole flex grooves _G 1 as viewed from the vertical _{direction, G 2, G 3, G} 3' each sole flex grooves _G 1 inside _{the, G} 2, G ₃ and G ₃ ′. Therefore, each of the sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ ₃ also extends substantially in the sole width direction.

As shown in FIG. 9, the sole bending grooves G ₁ and G ₂ are arranged at intervals in the front-rear direction of the sole across the metatarsophalangeal joint MP of the foot of the shoe wearer. The sole flexion groove (first sole flexion groove) G ₁ extends from the vicinity of the bone base of the first toe phalange DP ₁ (or the head of the first toe phalange PP ₁ ) on the instep side to the second middle phalanx of the toe. It extends through the vicinity of the head of MP ₂ toward the outer shell side. The sole flexion groove (second sole flexion groove) G ₂ is located behind the medial toe ball TE on the inner side of the instep, and extends from the central portion of the first toe metatarsal MB ₁ to the outer side of the fifth toe metatarsal MB. It extends toward the vicinity of the _5th head. Sole curved groove (third sole curved _groove) G 3, _{G 3} ', the first, is disposed between the second sole flex grooves _G 1, _{G 2,} first, second sole flex grooves It is arranged at a distance from G ₁ and G _{2 in the} front-back direction of the sole. The sole flexion groove (third sole flexion groove) G ₃ is a short-length groove (that is, a notch) arranged near the metatarsophalangeal joint MP on the inner instep side. The sole bending groove (third sole bending groove) G ₃ ′ extends from the outer shell side toward the central portion in the sole width direction through the fifth toe phalange DP ₅ .

The first and second sole bending grooves G ₁ and G ₂ are open at both the inner side end and the outer side end of the front foot F (see FIGS. 2 and 3 ). The third sole bending groove G ₃ is opened only on the inner instep side end of the forefoot F, and the third sole bending groove G ₃ ′ is opened only on the outer instep side of the forefoot F. (See Figure 1). The outsole 4 is divided into two outsole portions 4A and 4B in the forefoot F by the sole bending grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ (see FIG. 1 ). Further, in the region from the middle foot portion M to the heel portion H, the outsole 4 is divided into the outsole portions 4C ₁ and 4D on the inner side and the outsole portions 4C ₂ , 4C ₃ , 4C on the outer side. ₄ , divided into 4D (see FIG. 1). A recess 35 is formed in the center of the heel portion H of the sole structure 1, and the outsole portions 4C ₁ and 4C ₃ and 4C ₄ are spaced apart from each other in the sole width direction via the recess 35. As shown in FIGS. 7 and 8, the recess 35 is composed of a recess groove formed in the lower midsole 3.

As shown in FIGS. 10 to 12, the first sole bending groove G ₁ divides the outsole 4 into the outsole portions 4A and 4B (that is, the slit 40 that penetrates the outsole 4 in the thickness direction), In the slit 40 (that is, at a position corresponding to the slit 40), the groove 30 is formed in the lower surface 3b of the lower midsole 3. The second sole bending groove G ₂ divides the outsole 4 into the outsole portions 4B and 4C ₁ and 4C ₂ (that is, penetrates the outsole 4 in the thickness direction), and inside the slit 41 (that is, the slit 41). , At a position corresponding to the slit 41) and a concave groove 31 formed in the lower surface 3b of the lower midsole 3. The third sole bending groove G ₃ includes a slit 42 penetrating the outsole 4 in the thickness direction and a recess formed in the lower surface 3 b of the lower midsole 3 in the slit 42 (that is, at a position corresponding to the slit 42 ). And a groove 32. The third sole bending groove G ₃ ′ is formed in the slit 42 ′ that penetrates the outsole 4 in the thickness direction, and in the lower surface 3 b of the lower midsole 3 in the slit 42 ′ (that is, at the position corresponding to the slit 42 ′). It is composed of the formed groove 32'. In each figure, the position of the corrugated ridgeline 2b ₁ formed on the lower surface 2b of the upper midsole 2 is indicated by a black circle.

Here, the opening width and depth of each of the sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ will be defined as follows with reference to FIG. 13. In the figure, an example of the third sole bending groove G ₃ is shown as an example, but the same applies to other sole bending grooves.

As shown in FIG. 13, the third opening width of the sole bending groove G _3, the opening width W of the slit 42 of the outsole 4, as depth of the third sole curved groove G ₃ are, the lower midsole 3 is defined as the depth d of the concave groove 32 measured from the lower surface 3b of 3 (that is, the outsole attachment surface of the lower midsole 3). Specifically, as the values of the opening width W and the depth d,
W: 3 to 18 mm (preferably 7 mm)
d; 0.5 to 10 mm (preferably 2 mm)
Is set to.
In this example, the opening width w of the concave groove 32 formed on the lower surface 3b of the lower midsole 3 is smaller than the opening width W of the slit 42 of the outsole 4. At the opening edge of the groove 32, a rim 32r is provided which bulges downward (to the right in FIG. 13). The rim 32r is provided to reinforce the concave groove 32, prevent the outsole portion 4B from being displaced/separated, and identify the bonding position.

Both the upper and lower midsole 2 and 3 are made of a soft elastic member. Specifically, thermoplastic synthetic resins such as ethylene-vinyl acetate copolymer (EVA), foams thereof, polyurethane (PU), etc. Of thermosetting resin or foam thereof, or rubber material such as butadiene rubber or chloroprene rubber or foam thereof.

The hardness of the upper midsole 2 is higher than that of the lower midsole 3. Specifically, the hardness of the upper midsole 2 is set to, for example, 60±4C on the Asker C scale, and the hardness of the lower midsole 3 is set to, for example, 50±4C on the Asker C scale. The difference in hardness between the upper and lower midsoles 2 and 3 is preferably about 5C.

The outsole 4 is made of a hard elastic member, specifically, a thermoplastic resin such as thermoplastic polyurethane (TPU) or polyamide elastomer (PAE), a thermosetting resin such as epoxy, or a solid rubber. ing. The hardness of the outsole 4 is set to, for example, 60 A on the Asker A scale.

Next, the function and effect of this embodiment will be described.
When the forefoot portion F of the sole structure 1 is bent during running, the sole structure 1 includes the sole bending groove G ₂ on the rear end side of the front foot F and the sole bending grooves G ₃ , G _{3 at the} front-rear intermediate position. ′, and is sequentially bent along the sole bending groove G ₁ on the front end side.

At this time, both the lower surface 2b of the upper midsole 2 and the upper surface 3a of the lower midsole 3 have a corrugated surface, and the corrugated ridgeline 2b ₁ of the upper midsole 2 having a relatively high hardness is the outsole 4. sole curved groove _{G 1, G 2, G 3} , G 3 ' and are overlapped in the vertical direction, the outsole curved groove _G 1 of the sole _{4, G 2, G 3,} G 3' at the position of the relative ridge 2b ₁ of the lower surface of the wave-shaped upper midsole 2 of high hardness are arranged manner (see FIG. 1). That is, each ridge line 2b ₁ is arranged above the corresponding sole bending groove G ₁ , G ₂ , G ₃ , G ₃ ′, and is aligned with the sole bending groove G ₁ , G ₂ , G ₃ , G ₃ ′. They are opposed to each other (see FIGS. 2 to 4 and 10 to 13). Therefore, at the positions of the sole bending grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ of the outsole 4, the thick portion (that is, the high rigidity portion) of the high hardness upper midsole 2 having the corrugated surface on the lower surface 2b. ) Has been placed.

Therefore, when the forefoot part F tries to bend along the sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ of the outsole 4 when the sole structure 1 is bent, the sole bending grooves G ₁ , G _The thick portions of the relatively high hardness upper midsole 2 arranged at the positions of ₂ , G ₃ , and G ₃ ′ tend to bend at the same time. However, because these thick portions are high-rigidity portions, Local excessive bending along the sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ of the sole structure 1 is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, the flexibility of the forefoot F can be controlled, and as a result, the occurrence of energy loss due to local excessive bending can be prevented. ..

Although the preferred embodiment of the present invention has been described above, the application of the present invention is not limited to this, and the present invention includes various modifications. Some examples of modifications will be given below.

<First Modification>
In the above-described embodiment, the sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ provided in the front foot portion F of the sole structure 1 have slits (through grooves) 40, 41, 42 passing through the outsole 4, 42' and an example having concave grooves (bottomed grooves) 30, 31, 32, 32' formed in the lower midsole 3 have been shown, but the application of the present invention is not limited thereto.

14 to 21 show a sole structure for sports shoes according to a first modification of the present invention. In these drawings, the same reference numerals as those used in the above-mentioned embodiments indicate the same or corresponding parts. Here, indoor shoes are taken as an example of sports shoes. As shown in FIGS. 14 to 21, in the first modified example, the front leg portion F of the sole structure 1 is provided with sole bending grooves G ₁ , G ₂ , and G ₃ , and these sole bending grooves are provided. G ₁ , G ₂ , and G ₃ are configured by concave grooves (bottomed grooves) 45, 46, and 47 formed in the ground contact surface 4 b of the outsole 4, respectively. That is, the sole bending grooves G ₁ , G ₂ , and G ₃ do not penetrate the outsole 4.

In addition, the corrugated ridgeline 2b ₁ of the lower surface 2b of the upper midsole 2 vertically overlaps the sole bending grooves G ₁ , G ₂ , and G _{3 of the} outsole 4 (that is, each ridgeline 2b ₁ is corresponding sole flex grooves G _1, G _2, G ₃ of which is opposed to the upper) point, point, etc. a higher hardness than the upper midsole 2 is lower midsole 3 is the same as in example ..

The opening width and depth of each of the sole bending grooves G ₁ , G ₂ , and G ₃ will be defined as follows with reference to FIG. In the figure, an example of the third sole bending groove G ₃ is shown as an example, but the same applies to other sole bending grooves.

As shown in FIG. 21, the third opening width of the sole bending groove G _3, the distance W between the third sole opening edge of the curved groove G _3, the depth of the third sole curved groove G ₃ Is defined as the thickness d of the thin portion at the bottom of the third sole bending groove G ₃ . Specifically, as the values of the opening width W and the depth d,
W: 1 to 15 mm (preferably 4 mm)
d; 1-2 mm (preferably 1 mm)
Is set to.

When the forefoot part F of the sole structure 1 bends during exercise, the forefoot part F bends along the sole bending grooves G ₁ , G ₂ , and G ₃ . At this time, both the lower surface 2b of the upper midsole 2 and the upper surface 3a of the lower midsole 3 have a corrugated surface, and the corrugated ridgeline 2b ₁ of the upper midsole 2 having a relatively high hardness is the outsole 4. The sole bending grooves G ₁ , G ₂ , and G ₃ vertically overlap with each other, and at the positions of the sole bending grooves G ₁ , G ₂ , and G ₃ of the outsole 4, a relatively high hardness upper midsole is located. The ridge line 2b ₁ of the corrugated surface on the lower surface of 2 is arranged (see FIG. 14). That is, each ridge line 2b ₁ is arranged above the corresponding sole bending groove G ₁ , G ₂ , G ₃ and faces the sole bending groove G ₁ , G ₂ , G ₃ (FIGS. 15 to 15). See FIG. 21). Therefore, at the positions of the sole bending grooves G ₁ , G ₂ , and G ₃ of the outsole 4, the thick portion (that is, the high rigidity portion) of the high hardness upper midsole 2 having the corrugated surface on the lower surface 2b is arranged. ing.

Therefore, when the forefoot F during bending sole assembly 1 is to bend along the sole bending groove _{G 1,} G 2, _{G 3} outsole 4, the sole flex grooves _{G 1,} G 2, _{G 3} At the same time, the thick portions of the relatively high hardness upper midsole 2 arranged at the positions of 1 and 2 try to bend at the same time, but since these thick portions are highly rigid portions, the bending resistance is large, and the sole structure 1 Local excessive bending along the sole bending grooves G ₁ , G ₂ , and G ₃ is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, and the flexibility of the forefoot F can be controlled. As a result. It is possible to prevent the occurrence of energy loss due to local excessive bending.

<Second Modification>
In the embodiment and the first modified example, the corrugated ridgeline 2b ₁ formed on the lower surface 2b of the upper midsole 2 extends over the entire sole width direction (that is, from the inner shell side end portion to the outer shell side end portion). Although the extended example is shown, the application of the present invention is not limited to this.

22 to 25 show a sports shoe sole structure according to a second modification of the present invention. Here, running shoes are taken as an example of sports shoes. In these figures, the same reference numerals as those used in the above-mentioned embodiment indicate the same or corresponding parts.

As shown in FIGS. 22 and 25, in the front foot portion F of the sole structure 1, a recessed portion 28 that opens to the lower surface 2b side is formed in the center portion of the upper midsole 2 in the front-back direction and in the sole width direction. .. In this example, the recess 28 is a substantially rectangular bottomed hole that is formed in the lower surface 2b. A corrugated surface is formed on the bottom surface of the concave portion 28, and the ridge line and the valley line of the corrugated shape are shown by broken lines in FIG. During the drawing, the plurality of dashed lines are marked, of these broken lines, broken lines 2b ₁ shows the waveform-shaped ridge of the bottom surface of the recess 28, between the dashed line 2b ₁ adjacent in the longitudinal direction A broken line 2b ₂ of ₂ indicates a corrugated valley line on the bottom surface of the recess 28. As shown in the figure, the wave-shaped ridge lines and valley lines of the concave portion 28 of the upper midsole 2 are arranged only in the sole width direction central portion of the front foot portion F, and the inner instep side end portion of the front foot portion F and It does not extend to the outer shell side end. Therefore, the corrugated surface of the concave portion 28 of the upper midsole 2 does not appear at the inner and outer shell side end portions of the front foot portion F (see FIGS. 23 and 24).

Each of the ridge lines 2b ₁ and the valley lines 2b ₂ extends in the sole width direction while being gently curved. Here, the word “substantially” is included not only in the case of the strict width direction in which the ridgeline 2b ₁ and the valley line 2b ₂ are orthogonal to the sole front-rear direction centerline, as in the above-described embodiment, It is also intended to include the case where it intersects at an angle with this. Further, each of the ridge lines 2b ₁ and the valley lines 2b ₂ gradually inclines toward the inward side along the forward direction along the moving direction of the load during traveling, and the corrugated shape of the bottom surface of the recess 28 is formed. Substantially progresses in the front-back direction of the sole. The word "substantially" is used here not only when the wave shape is in the strict sole front-rear direction that travels along the sole front-rear direction centerline, but also when the wave shape travels diagonally at an angle. Is also included.

A midsole insert 38 is housed in the recess 28 of the upper midsole 2. The midsole insert 38 is a substantially rectangular plate-shaped member and has a size and shape corresponding to the recess 28, but its upper surface 38a is not corrugated, and the upper surface 38a is flat. The surface is a curved surface or a gentle curved surface, and is in contact with the corrugated surface of the bottom surface of the recess 28 of the upper midsole 2. That is, the upper surface 38 a of the midsole insert 38 is in contact with each ridgeline 2 b ₁ of the corrugated surface of the recess 28 of the upper midsole 2. A void S is formed between the upper surface 38 a of the midsole insert 38 and each valley line ₂ b ₂ of the corrugated surface of the recess 28 of the upper midsole 2.

As shown in FIG. 22, the sole structure 1 has a plurality of sole bending grooves G ₁ , G ₂ , G ₃ , G ₃ ′ on the bottom surface side of the front foot portion F. The midsole insert 38 is arranged in a region sandwiched between the sole bending grooves G ₁ and G ₂ in the front-back direction of the sole. The sole bending groove G ₃ ′ is arranged at a position that vertically overlaps with any _one of the corrugated ridgelines 2 b ₁ of the concave portion 28 of the upper midsole 2. That is, either the ridge 2b ₁ corrugated midsole second recess 28, sole curved groove G _{3 'disposed} above of the sole bending groove G _3' are opposed to. Here, a part of the ridge line 2b ₁ vertically overlaps with the sole bending groove G ₃ ′ at the center portion of the front foot F in the sole width direction, and the inside of the sole bending groove G ₃ ′ is seen from the vertical direction. And is extended along the sole bending groove G ₃ ′.

As shown in FIGS. 23 to 25, the upper midsole 2 extends from the heel portion H of the sole structure 1 through the middle foot portion M to the forefoot portion F, but the lower midsole 3 includes the sole structure body. 1 is mainly provided only on the heel portion H. In the heel portion H, a corrugated sheet 5 is arranged between the upper and lower midsoles 2 and 3. The corrugated sheet 5 has a wave shape that advances in the front-back direction of the sole, and is made of a hard elastic member. A corrugated shape corresponding to the corrugated shape of the corrugated sheet 5 is formed on each mating surface of the upper and lower midsole 2 and 3 that sandwich the corrugated sheet 5, and a cushion hole 50 is formed as necessary.

The outsole 4 is divided into two outsole portions 4A and 4B in the front foot F by the sole bending grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ provided on the bottom surface side of the front foot F of the sole structure 1. In the region from the middle foot M to the heel H, the outsole 4 is divided into outsole parts 4C ₁ , 4C ₁ ′, 4D on the instep side and the outsole part 4C on the outstep side. It is divided into ₂ , 4C ₃ , 4C ₄ , and 4D (see FIG. 22 ).

As shown in FIGS. 22 to 24, the first sole bending groove G ₁ divides the outsole 4 into the outsole portions 4A and 4B (that is, the slit 40 that penetrates the outsole 4 in the thickness direction), In the slit 40 (that is, at a position corresponding to the slit 40 ), a concave groove 25 is formed in the lower surface 2b of the upper midsole 2. The second sole bending groove G ₂ divides the outsole 4 into the outsole portions 4B and 4C ₁ ′, 4C ₂ (that is, penetrates the outsole 4 in the thickness direction), and in the slit 41 ( That is, it is composed of the concave groove 26 formed in the lower surface 2b of the upper midsole 2 (at a position corresponding to the slit 41). The third sole bending groove G ₃ includes a slit 42 that penetrates the outsole 4 in the thickness direction and a recess formed in the lower surface 2b of the upper midsole 2 in the slit 42 (that is, at a position corresponding to the slit 42). And the groove 27. The third sole bending groove G ₃ ′ is provided on the slit 42 ′ that penetrates the outsole 4 in the thickness direction and on the lower surface 2 b of the upper midsole 2 in the slit 42 ′ (that is, at the position corresponding to the slit 42 ′). The groove 27' is formed.

The opening width and the depth of each of the sole bending grooves G ₁ , G ₂ , G ₃ , and G ₃ ′ are defined in the same manner as in the above embodiment. That is, as the opening width of each sole bending groove, the opening width of each slit of the outsole 4 is adopted, and as the depth of each sole bending groove, the lower surface 2b of the upper midsole 2 (that is, the upper midsole 2 Use the depth measured from the outsole pasting surface). Specific numerical values are the same as those shown in the above embodiment.

The upper midsole 2 and the midsole insert 38 are both made of a soft elastic member as in the above-mentioned embodiment, but unlike the above-mentioned embodiment, the hardness of the upper midsole 2 is higher than that of the midsole insert 38. It does not necessarily have to be high, and there is no difference in hardness between the two.

The reason is as follows.
Since the corrugated surface of the bottom surface of the concave portion 28 of the upper midsole 2 is in contact with the flat upper surface 38a of the midsole insert 38, only the ridgeline 2b ₁ of the corrugated surface is in contact with the upper surface 38a, A void S is formed between the valley line 2b ₂ and the upper surface 38a. Therefore, even if the upper midsole 2 and the midsole insert 38 have the same hardness, the rigidity of the upper midsole 2 becomes higher than the other parts because the thickness of the ridgeline 2b ₁ of the upper midsole 2 increases.

When the forefoot portion F of the sole structure 1 is bent during running, the sole structure 1 includes the sole bending groove G ₂ on the rear end side of the front foot F and the sole bending grooves G ₃ , G _{3 at the} front-rear intermediate position. ′, and is sequentially bent along the sole bending groove G ₁ on the front end side.

At this time, the bottom surface of the concave portion 28 of the upper midsole 2 has a corrugated surface, and the portion of the ridgeline 2b ₁ (that is, the thick high-rigidity portion) vertically overlaps the sole bending groove G ₃ ′. The sole bending groove G ₃ ′ is arranged so as to face the sole bending groove G ₃ ′ (see FIGS. 22 and 25).

Therefore, when the forefoot part F tries to bend along the sole bending groove G ₃ ′ of the outsole 4 when the sole structure 1 is bent, the upper midsole 2 arranged at the position of the sole bending groove G ₃ ′. The portion of the ridgeline 2b ₁ of the corrugated surface of the same tends to bend at the same time, but since this is a high-rigidity portion, the bending resistance is large, and a local excess along the sole bending groove G ₃ ′ of the sole structure 1 is excessive. Bending is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, and the flexibility of the forefoot F can be controlled. As a result. It is possible to prevent the occurrence of energy loss due to local excessive bending. The midsole insert 38 may be extended to either the inner instep side end or the outer instep side end of the front foot portion F,

<Third Modification>
FIG. 26 shows a third modification of the present invention and corresponds to FIG. 2 of the above embodiment. 26, the same reference numerals as those in FIG. 2 indicate the same or corresponding portions. Although the hardness of the upper midsole 2 is set higher than that of the lower midsole 3 in the above-described embodiment, the hardness of the lower midsole 3 is reversed in this third modified example. Is set higher than the hardness of the upper midsole 2.

Specifically, the hardness of the lower midsole 3 is set to, for example, 60±4C on the Asker C scale, and the hardness of the upper midsole 2 is set to, for example, 50±4C on the Asker C scale. The difference in hardness between the upper and lower midsoles 2 and 3 is preferably about 5C.

Further, the phases of the upper and lower midsoles ₂ and _{3 with} respect to the corrugated sole bending grooves G ₁ , G ₂ and G ₃ are different from those in the above embodiment. In the above embodiment, the corrugated ridgeline 2b ₁ of the upper midsole 2 is arranged so as to face each of the sole bending grooves G ₁ , G ₂ , G ₃ , but in the third modification, the lower midsole 3 is The corrugated ridgeline 3a ₁ is arranged so as to face each of the sole bending grooves G ₁ , G ₂ , and G ₃ .

In this way, the corrugated ridgeline 3a _{1 on} the upper surface of the lower midsole 3 having a relatively high hardness is arranged at the positions of the respective sole bending grooves G ₁ , G ₂ , and G ₃ , that is, the high hardness. Since the thick portion (high-rigidity portion) of the lower midsole 3 is arranged, the front foot portion F of the sole structure 1 extends along each of the sole bending grooves G ₁ , G ₂ , and G ₃ during exercise such as running. When attempting to bend, the thick portion (high rigidity portion) of the relatively high hardness lower midsole 3 arranged at the positions of the sole bending grooves G ₁ , G ₂ , G ₃ tries to bend at the same time and has a large bending resistance. And the local excessive bending along the sole bending grooves G ₁ , G ₂ , and G ₃ of the sole structure 1 is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, the flexibility of the forefoot F can be controlled, and as a result, the occurrence of energy loss due to local excessive bending can be prevented. ..

<Fourth Modification>
FIG. 27 shows a fourth modification of the present invention and corresponds to FIG. 18 of the first modification. 27, the same reference numerals as those in FIG. 18 indicate the same or corresponding portions. In the above-described embodiment, the example in which the corrugated surface is formed on both the upper and lower midsoles 2 and 3 is shown. However, in the fourth modification, the corrugated surface is formed only on the lower surface 2b of the upper midsole 2. The upper surface 3a of the lower midsole 3 does not have a corrugated surface, but has a flat surface or a gently curved surface.

On the upper surface 3a of the lower midsole 3, ridge 2b ₁ of the corrugated surface of the lower surface 2b of the upper midsole 2 is in contact with, the valley line 2b ₂ are not in contact, the valley line 2b ₂ and the lower midsole A space S is formed between the upper surface 3 a of the metal plate 3 and the upper surface 3 a. In addition, the ridgeline 2b ₁ of the upper midsole 2 is opposed to the positions of the respective sole bending grooves G ₁ and G ₂ of the outsole 4, and the thick portion (that is, high rigidity portion) of the upper midsole 2 is arranged. Has been done.

As described above, since the thick portion (high rigidity portion) of the upper midsole 2 is arranged at the positions of the respective sole bending grooves G ₁ and G ₂ , the front foot portion of the sole structure 1 during exercise such as running. when F is to bend along the sole flex grooves G _1, G _2, the thick portion of the sole flex grooves G _1, the upper midsole 2 arranged at the position of G ₂ (highly rigid portion) is simultaneously bent An attempt is made to generate a large bending resistance, and local excessive bending along the sole bending grooves G ₁ and G ₂ of the sole structure 1 is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, the flexibility of the forefoot F can be controlled, and as a result, the occurrence of energy loss due to local excessive bending can be prevented. ..

In the fourth modified example, as in the second modified example, the hardness of the upper midsole 2 does not necessarily have to be higher than the hardness of the lower midsole 3, and there is no difference in hardness between the two. Good. This is because even if the upper and lower midsoles 2 and 3 have the same hardness, the rigidity of the ridge line 2b ₁ of the upper midsole 2 is higher than that of the other parts.

<Fifth Modification>
FIG. 28 shows a fifth modification of the present invention, and corresponds to FIG. 18 of the first modification. 28, the same reference numerals as those in FIG. 18 indicate the same or corresponding portions. In the above-described embodiment, an example in which the corrugated surface is formed on both the upper and lower midsoles 2 and 3 is shown. However, in the fifth modification, the corrugated surface is formed only on the upper surface 3a of the lower midsole 3. Therefore, the lower surface 2b of the upper midsole 2 does not have a corrugated surface, but has a flat surface or a gently curved surface.

On the lower surface 2b of the upper midsole 2, ridge 3a ₁ of the corrugated surface of the upper surface 3a of the lower midsole 3 is in contact with, the valley line 3a ₂ are not in contact, the valley line 3a ₂ and the upper midsole A space S is formed between the lower surface 2b and the lower surface 2b. The ridgelines 3a ₁ of the lower midsole 3 are opposed to the positions of the respective sole bending grooves G ₁ and G ₂ of the outsole 4, and the thick portion (high rigidity portion) of the lower midsole 3 is arranged. ing.

As described above, since the thick portion (high rigidity portion) of the lower midsole 3 is arranged at the position of each of the sole bending grooves G ₁ and G ₂ , the front foot portion of the sole structure 1 during exercise such as running. when F is to bend along the sole flex grooves G _1, G _2, the thick portion of the sole flex grooves G _1, the lower midsole 3 placed at the position of G ₂ (highly rigid portion) is simultaneously bent An attempt is made to generate a large bending resistance, and local excessive bending along the sole bending grooves G ₁ and G ₂ of the sole structure 1 is suppressed. As a result, the sole structure 1 can be evenly bent in the front-back direction of the sole, the flexibility of the forefoot F can be controlled, and as a result, the occurrence of energy loss due to local excessive bending can be prevented. ..

In the fifth modified example, the hardness of the lower midsole 3 does not necessarily have to be higher than the hardness of the upper midsole 2, and there is no difference in hardness between the two. This is because even if the upper and lower midsoles 2 and 3 have the same hardness, the rigidity of the ridgeline 3a ₁ of the lower midsole 3 is higher than that of the other parts.

<Sixth Modification>
In the embodiment and the first, third to fifth modifications, the corrugated ridgeline 2b ₁ of the upper midsole 2 or the corrugated ridgeline 3a _{1 of the} lower midsole 3 is spread over the entire sole width direction (that is, , over from the medial end of the forefoot portion F over the entire length direction of the outer toward the instep side end portion), or curved groove, the vertical direction and the sole bending groove _{G 1, G 2, G 3} , G 3 ' Although the wrapped example is shown (see FIG. 1, FIG. 14, etc.), the application of the present invention is not limited to this.

Part of each of the ridge lines 2b ₁ and 3a ₁ may overlap the sole bending grooves G ₁ , G ₂ , G ₃ and G ₃ ′ in the vertical direction. As the overlapping region, for example, a region in which one or two of the instep side portion, the outer instep side portion, or the center portion in the sole width direction of the forefoot F is combined is considered. As a specific example, for example, the ridge line 2b ₁ vertically overlaps the sole bending groove G _{2 at} the inner instep side of the forefoot F (that is, the ridge line 2b ₁ vertically opposes the sole bending groove G _2). However, a case where the center portion of the front foot F in the sole width direction and the outer shell side portion do not vertically overlap (that is, the ridge line 2b ₁ does not vertically face the sole bending groove G ₂ ) and the like are cited. Be done. In this case, a supplementary explanation will be given with reference to FIG. 1 and FIG. 14. Although the ridgeline 2b ₁ is located in the sole bending groove G ₂ at the inner instep side portion, the sole is provided at the sole width direction central portion and the outer instep side portion. It is located outside the bending groove G ₂ . The same applies to the aspect of overlap with other sole bending grooves.

<Seventh Modification>
In the embodiment and the first and second modified examples, an example is shown in which the sole bending grooves G ₁ and G ₂ are opened at both the inner instep side end and the outer instep side end of the forefoot F. The sole bending grooves G ₁ and G ₂ may be opened only on one of the inner instep side end and the outer instep side end of the forefoot F (thus, closed on the other side). Alternatively, the sole bending grooves G ₁ and G ₂ may be closed at both the inner instep side end and the outer instep side end of the forefoot F. Similarly, the sole bending groove G ₃ may be closed at the inner shell side end portion, and the sole bending groove G ₃ ′ may be blocked at the outer shell side end portion. Further, each sole bending groove does not have to be a groove that is continuous in the groove arrangement direction, but may be a groove that extends intermittently in the groove arrangement direction. Regarding the corrugated ridge 2b ₁ of the upper midsole 2, it may be a length corresponding to the groove length of each sole curved groove. For example, when the sole flexion groove is closed at both the inner side end and the outer side end of the front foot F, the corrugated ridgeline 2b ₁ of the upper midsole 2 is It is not necessary to extend to the side end and the outer shell side end, and the wavy shape of the upper midsole 2 may not appear at the inner shell side end and the outer shell side end.

<Other modifications>
The embodiments and modifications described above are to be considered in all respects merely as exemplifications of the invention and are not limiting. Those skilled in the art to which the present invention pertains, even if not explicitly described herein, when considering the above teachings without departing from the spirit and essential characteristics of the invention. Various modifications and other embodiments adopting the principle of can be constructed.

<Other application examples>
In the embodiment and each of the modifications, an example in which the sole structure is applied to running shoes or indoor shoes has been shown, but the application of the present invention is not limited to these, and the present invention is not limited to the above. It is similarly applicable to sports shoes.

INDUSTRIAL APPLICABILITY As described above, the present invention is useful for a sole structure of a sports shoe that requires control of the flexibility of the forefoot region.

1: Sole structure

2: Upper midsole 2b: Lower surface 2b ₁ : Ridge line 2b ₂ : Valley line 25, 26, 27, 27': Recessed groove

3: Lower midsole 3a: Upper surface 3a ₁ : Ridge line 3a ₂ : Valley line 3b: Lower surface 30, 31, 32, 32': Groove 38: Midsole insert 38a: Upper surface

4: Outsole 4b: Grounding surface 40, 41, 42. 42': Slit 45, 46, 47: Recessed groove

G ₁ : first sole bending groove G ₂ : second sole bending groove G ₃ , G ₃ ′: third sole bending groove

F: Forefoot MP: Metatarsophalangeal joint

S: Void

European Patent Application Publication No. 3146862 (see paragraphs [0004], [0018] to [0020], FIGS. 1 and 2) Japanese Patent No. 3403952 (see FIG. 1)

Claims (10)

A sole structure arranged in the forefoot region of a sports shoe,
An upper midsole, which is arranged on the upper side of the forefoot region, has an upper surface that is a sole contact surface with which the sole of the wearer comes into contact, and is made of a soft elastic member
A lower midsole that is disposed below the forefoot region and has an upper surface that is provided so as to contact the lower surface of the upper midsole, and a lower midsole that is made of a soft elastic member,
An outsole that is disposed on the lower surface of the lower midsole and that has a grounding surface that contacts the road surface and that has a plurality of sole bending grooves that extend substantially in the sole width direction,
Both the lower surface of the upper midsole and the upper surface of the lower midsole have corrugated surfaces that are substantially corrugated in the front-back direction of the sole and have thick portions, A ridge line that is a line formed by connecting convex vertices of a shape, and a valley line that is a line formed by connecting the deepest part of the corrugated concave shape substantially extends in the sole width direction, and the upper midsole and the The lower midsole has a hardness difference,
At least a part of the corrugated ridgeline of the upper midsole having a hardness relatively higher than that of the lower midsole vertically overlaps with each of the plurality of sole bending grooves of the outsole. And, the thick part of the upper midsole is arranged at each position of the plurality of sole bending grooves, or the thicker part of the lower midsole having a relatively high hardness with respect to the upper midsole. At least a part of the wavy ridgeline overlaps each of the plurality of sole bending grooves of the outsole in the vertical direction, and the thick portion of the lower midsole bends the plurality of soles. Located in each position of the groove ,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
The ridge line of the corrugated shape, in the instep side portion of the forefoot region, the outer instep side portion, or in the sole width direction central side portion, overlaps with each of the sole bending grooves in the vertical direction,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
The plurality of sole bending grooves are composed of first and second sole bending grooves that are arranged at intervals in the sole front-rear direction with the middle toe joint of the foot of the shoe wearer interposed therebetween.
The sole structure of a sports shoe, which is characterized by that. In claim 3,
A third sole bending groove is provided between the first and second sole bending grooves, and the third sole bending groove is spaced from the first and second sole bending grooves in the sole front-rear direction. Are placed apart from each other,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
Each of the sole bending grooves is open to at least one of the inner shell side end portion and the outer shell side end portion of the forefoot region,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
Each of the sole bending grooves is closed on both the inner instep side end and the outer instep side end of the forefoot region,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
Each of the sole bending grooves has a slit that penetrates the outsole in the thickness direction,
The sole structure of a sports shoe, which is characterized by that. In claim 7,
Further having a groove formed in the lower surface of the lower midsole at a position corresponding to the slit,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
The ridge line and the valley line of the wavy shape, extending over the entire sole width direction of the forefoot region,
The sole structure of a sports shoe, which is characterized by that. In claim 1,
The ridge line and the valley line of the wavy shape are arranged only in the sole width direction central side portion of the forefoot region,
The sole structure of a sports shoe, which is characterized by that.

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